%0 Conference Paper %B Materials Research Society Spring Meeting %D 2005 %T Time dependent parallel resistance in a Schottky contact %A Takshi, A %A Madden, J D %A Fok, C W %A Warren, M R %C San Francisco %I Materials Research Society %P I3.35 pp. 1-6 %U http://www.mrs.org %V 871E %X The DC characteristics of Schottky contacts between regioregular Poly (3-hexylthiophene) and aluminum are studied in forward and reverse bias regimes. Current-voltage curve of the junction in the reverse bias shows a resistive path in parallel with the expected Schottky contact. This is a sign of ohmic contact between the organic semiconductor and metal in some regions. Reduction of this parallel resistance and degradation of the Schottky junction are observed over two weeks of testing. Accumulation of undesired ions or the diffusion of aluminum atoms in the semiconductor are mechanisms that may be the reason of ohmic behavior in some regions.